teams: ephemeral lifecycle for Scheduled + Triggered planner modes

Migration 0033: adds teams.lifecycle ('permanent' | 'ephemeral') and a
topology_runs.team_id back-ref with a partial index for the sibling-in-
flight check.

cm-db repo:
- teams::insert_team_with_lifecycle (insert_team keeps the permanent default)
- topology_runs::enqueue_run_for_team (populates team_id)
- topology_runs::check_ephemeral_teardown — atomic SELECT that only
  returns Some when the team is ephemeral AND no siblings are still
  queued/running; carries the workspace + bound claw ids for cleanup.

cm-api:
- topology_worker post-terminal hook maybe_teardown_ephemeral_team
  runs deprovision_claw on each bound claw (best-effort; failures log
  but don't block Postgres deletion), then hard_purge each agent row,
  then delete_team.
- routes::teams::build_team_with_lifecycle (build_team keeps default);
  run_team enqueues with team_id.
- planner ScaffoldRequest gains mode; lifecycle_for(mode) sets the team
  to ephemeral for scheduled + triggered, permanent otherwise.

Frontend MasterPlannerModal passes mode in the scaffold payload so the
backend can derive lifecycle without duplicating the mode taxonomy.

Tests: 3 new (returns claws when no siblings, holds when siblings queued,
ignores permanent teams). 10/10 topology_jobs green; workspace clippy
--tests clean.

crates/cm-api/src/routes/teams.rs

@@ -56,6 +56,30 @@ pub(crate) async fn build_team(
     name: &str,
     kind_str: &str,
     members: &[TeamMemberInput],
+) -> Result<(Uuid, Vec<Uuid>), ApiError> {
+    build_team_with_lifecycle(
+        state,
+        workspace_id,
+        user_id,
+        name,
+        kind_str,
+        members,
+        "permanent",
+    )
+    .await
+}
+
+/// Same as `build_team` but with an explicit `lifecycle` (`permanent` |
+/// `ephemeral`). Ephemeral teams are torn down by the topology_worker after
+/// their last run terminates — used by the Scheduled + Triggered planner modes.
+pub(crate) async fn build_team_with_lifecycle(
+    state: &AppState,
+    workspace_id: cm_domain::WorkspaceId,
+    user_id: cm_domain::UserId,
+    name: &str,
+    kind_str: &str,
+    members: &[TeamMemberInput],
+    lifecycle: &str,
 ) -> Result<(Uuid, Vec<Uuid>), ApiError> {
     if members.is_empty() {
         return Err(ApiError::BadRequest);
@@ -101,13 +125,14 @@ pub(crate) async fn build_team(
 
     let team_id = Uuid::now_v7();
     let graph_json = serde_json::to_value(&graph).map_err(|_| ApiError::Internal)?;
-    cm_db::repo::teams::insert_team(
+    cm_db::repo::teams::insert_team_with_lifecycle(
         &state.pool,
         team_id,
         workspace_id,
         name,
         kind.as_str(),
         &graph_json,
+        lifecycle,
     )
     .await?;
     for (i, node) in graph.nodes.iter().enumerate() {
@@ -373,12 +398,13 @@ pub async fn run_team(
     let team = cm_db::repo::teams::get_team(&state.pool, id, user.workspace_id).await?;
     crate::quota::enforce_new_run(&state, user.workspace_id).await?;
     let run_id = Uuid::now_v7();
-    cm_db::repo::topology_runs::enqueue_run(
+    cm_db::repo::topology_runs::enqueue_run_for_team(
         &state.pool,
         run_id,
         user.workspace_id,
         &body.task,
         &team.graph,
+        id,
     )
     .await?;
     Ok((